Apparatus for recovering solvents.



' LYNAHY.

APPARATUS FOR RECOVERING SOLVENTS.

APPLICATION FILED OCT. l5, 19l2.

. LNQQQ OOOOOOOOODUOQOOOO000009000000000 i STATES BAT-ENT OFFICE.

um Luni, or New Yonx, salomon 'ro E. r. u rom' amours :com or wrmrmeron;nmwama, Aeonron'rron or maw misser. .seminaires ron ucovmzmc sonvmrrs.

Patenten May 29, 1917.

Application mea ommis, 1912. serial no. mmc.

Tacll whom it may concem:

Be it' known that 1,; JAMES LYNAH, of

Newburgh, in the county of Orange and .in

the State of New York, have invented a certain new and TusefulImprovement in Apparatus for Recoverin Solvents, and do hereby declarethat the allowing 1s a full, clear, and exact idescription thereof.

.My invention relates particularly to a method .andmeans' for recoveringsolventsY usedin coatin compositions, although' it may be adapte to u sein any other connec tion"where it is desired to recover f's'olvents; Myinvention is particularly applicable to the recovery'of .solventsfrom.coatin of paper or textile fabrics containing india rubber, pyroxylin,011s, paints or'varmshes, and employing volatile solvents suchas`benzol, alcohol, ether, acetoneor turpentme:I

The object ofmy inventionz 1s to provide a process fand. apparatus for'carrymg'out Vthe same, iin which avery' large percentage ofthe solventutilizedmay be recovered. in the drying operation; 'infwhich 'the drylngoperation is eectedr'with the. greatest de-4 grec of-rapidityyandwin.which the danger of'serious explosions 1s m1n1m1zed. A urtherobjectofimy 'invention 'is to'enable the coating operationsto be carried outwith the smallest possible amountof laborand with 4the greatest degreeofuniformlty of result. Further objects of my inventlon are to provide'agnapparatus ofthe kind described, 'w'hich is constructed with "aclosed chamber Vin which the coating is applied-to the surface 'operatedupon in a closed, vapor-ti'glfit` chamber; to effectively spread thematerials in 'said chamberf; 'to'mainta1n the surface operated upo'n`taut 'so as to avold wrinkles; toprevent the escapeofjyapors 'at thepoint where the'iiexible matemal for receiving 'the coating entersleaves the apparatus; and to provide 'a cover which 1s loosely supportedupon the top of the apparatus to avoiddama'ge in case of an explosion. yL

As ilh'lstrative forms of apparatus which may be use'd for carry-mg 'outmy process, I have 'shown twoA different forms iqf appae ratas in the'accompanying ldrawmgs, 1n which# AFi re 1 represents a'side elevatlonof one Vforni of apparatus which maybe used for carrying but myprocessythe apparatus In'Fig. 1, I show a continuous strip of 4 paper or'textile fabric 1 which is conducted over a' 'supporting roller 2, Y andthence around a spreading roller?,4 which may-.be constructed irl-anydesired-manner to move the `tw'o' 'free Aends;- of the cloth laterallyto remove' the wrinkles from the same. From thisp'oint-'the-web ofmaterial to be coated passesl through a slot into a chamber 4 having'atitsfront, immediately above the web '1, adool' 5.' Within the chamber 4the web i-ssupported upon a pair of-,idler rollers 6 and between theserollers a knife 7 is' provided for spreading'orut upon-the surface ofthegoods in a uniform .layer a coating of any ldesired compositioncontaininga volatilesolvent, such' as pyroxyln dissolved inamixture 'ofsolvents, for example, benzol,-a1'eoho1,' etc., -ledr into the chamberin front of'the knife by means of a feed pipe 8. lThe chamber 4 isso'constructed that all of the joints are-as tight as-possibley `toprevent the escape of the 'vaporized' solvent. From the chamber 4 theweb, together 'with the solvent vapors which accumulate in the chamber4, pass into a long, fiat metal-lined evaporatng` chamber-9, havingal-plu'rality of idler rollers 10'to support the traveling web.immediately above the traveling web there is a series of radiator coils11 which is adapted '.tofreceive a current of hot water or i'steam "atthe end farthest removed from the pointf-of entry of the web to becoated and adapted to discharge the same at 'the othervend ofthe-chamber. 'By this meansl the coated web will begradually same at theend from which the travelingl web is discharged, by means of a pipe 1d,and being discharged 'om the same at the other end by means of a pipe15. The mixed air and evaporated solvent which are conducted' from` theevaporating chamber through the pipe 15 are led into a condenser 16formed with a circuitous pamageway l? by the presence of aplurality ofopposltely directed baiiie plates 18. A cooling coil 19 adapted to befed with cold water or other coolin agent, is situated in the passageway1%. llhe solvent which is condensed 1n the condenserv 16 is conductedaway through a discharge `pipe 20 to any suitable receptacle. From thecondenser 16 the air and any residual, uncondensed vapor are led bmeanso a pipe 2l to a rotary fan 22 whi again returns the same to theevaporating chamber through a reheater 23 containing heating coils 23a,andthe pi e 14, which is connected to the reheater. leaving the.evaporating chamber, the coated web drawn through a pair of felt strips24 by vmeans of a tension roller 25 over which the web is conducted, andfrom this point the web passes over an idler roller 26 to the surface ofa horizontal belt conveyor 27, where the coating is allowed toharden'before the web is `finally wound into rolls. The presence of thefelt strips 24 e'ectually prevents any vapors from being dragged out ofthe evaporating chamber by the traveling web.

In Fig. 2, I have shown a type of apparatus which is constructed exactlythe same as that shown in Fig. 1,except that between the fan 22 and thereheater 23, there located a trap' 28 to receive any solvent which iscondensed between the fan and the reheater, this trap 8 being connectedby a pipe 29 with the discharge pipey 20,. and near the bottom of thetrap 28 there is located an upwardly directed vent pipe 30 to admit airyand allow any accumulated solvent to be discharged from the trap whendesired through the branch 29 ofthe pipe 30.

In oarryingout' my process, the traveling web of paper or textile fabricis fed into a coating chamber in which it is provided with a uniformcoating of the desired composition containing solvent. chamber is soarranged that the escape of any of the solvent vapors is prevented asfar as pos,- sble. This is brought about by the fact that the coatingcomposition is lcd into the chamber by means of a pipe, and the use ofthe spreader obviates the necessity of frequent access to the chamber toremove wrinkles. The vapors which accumulate in the chamber 4 areultimately dragged into the evaporating chamber 9 through the traveling`web. l, whence they are withdrawn and condensed. As the traveling web ipasses from this chamber it is received by the evaporating chamber whichis arranged with the heating and drying coils above the' same toA avoidany drippings which might be enplosive in nature, from falling upon thecoils om the' c oated web. The heating coils heat the traveling webprincipally by radiantheat,the heat being applied in this mannerdirectly to the surface to be dried. This chamber is,rurthermore,' soarranged that the danger of explosion is minimized as the size of thechamber is made as small as possible to reduce the amount of solventvapor contained therein, and as the cover is made so that it may bereadily elevated in case of an explosion to relieve the pressure withinthe evaporating chamber. 'lhe presence of this particular type of coveralso enables the heating devices on the interior, which are locatedabove the surface of the co-ated web to be more readily accessible. Thecoated web rapidly dried in the evaporating chamber owing to the factthat the coils 11 radiate directly against the surfaceto be dried, anddo not have to pass through the lower, uncoated side of the web.,Furthermore, the rapid circulation of the air through the evaporatingchamber enables the evaporation and drying to be effected as rapidly asis consistent with the production of a uniform smooth surface. At thesame time, the` solvent which is taken up by the circulating current ofair is quickly condensed in the condenserl, and is led away to anyconvenientcondenser where it may berecovered and used againinpreparingthe coatingcomposition. The air and uncondensed vapors which passthrough the condenser are again used by being passed through thereheater and into the evaporating chamber, theloss of any vuncondensedsolvent vapors being thus entirely obviated. It sometimes happens that asmall percentage of the uncondensed vapor becomes condensed andaccumulates between the' fan and the reheater prior to the rentry of thecurrent of air into the evaporating chamber, and if desired, the processmay be operated with an apparatus such as that shown in Fig 2 in orderto collect the solvent thus condensed between the 'fan and the'reheater, and the solvent condensed `in this manner may be conducted tothe discharge lill@ pipe which leads from the condenser. The l that manychanges may be made therein Without departing from the fundamentalprinciples thereof.

I claim:

1. In a device of the character' described, an evaporating chamber',means for supporting a coated web in the same, a Vaporftight coverloosely supported over the saine and an air pipe connected to saidcover.

2. In a device of the character described, an evaporatiner chamber,means for supportingI a coated web in the same, and a vaportight coverloosely supported over the same in a castor oil seal.

3. In a device of the character described, a feedingr chamber for acoating,r material, an evapo'rating chamber, means for supporting;I acoated web in the same, and a vapor-tight cover loosely supported overthe feeding and evaporating chambers.

4. In a device of the character described,

a feeding chamber for a coating material, an v evaporatingr chamber,means for supporting as coated web in the same, and a vapor-tight coverloosely supported over the feeding and evaporating chambers in a liquidseal.

5. In a device of the character described, a feeding chamber for acoating material, an evaporating chamber, means for support ing' acoated web in the Same, and a vapor` tight cover. loosely supported overthe feeding: and evaporating,r chambers located at the outer edge of thecover, and alsobetween the feeding chamber and the evaporating chamber.

In testimony that I claim the foregoing I have hereunto set my hand.

JAMES LYNAII.

Witnesses:

W. R. Umm,- It. B. I'IEYWARD.

